Racecadotril or acetorphan, (±)-N-[2-[(acetylthio)methyl]-1-oxo-3-phenylpropyl]glycine phenylmethyl ester, is a pediatric and non pediatric antidiarrheal drug having a pure antisecretory mechanism, used to treat acute diarrhea. Chemically, it is a synthetic dipeptide that has the ability to inhibit the peripheral enkephalinase. The antidiarrheal effect is obtained due to a decrease in the secretion of water and intestinal electrolytes, secreted into the lumen of the digestive tract by the myenteric and submucosal plexus.
This substance has been studied since 1993 and patented by the Bioprojet Pharma laboratories; it is marketed in some countries of the world under the names Hidrasec, Tiorfan, Tiorfix.
This drug, however, has the problem of having a low solubility and a very low wettability in water, which negatively affects its bioavailability. In fact, the aqueous solubility and dissolution rate are two key factors that influence the absorption of a drug in the intestinal tract and thereby its bioavailability for oral administration.
The object of the present invention is therefore to provide a pharmaceutical composition of racecadotril having a higher dissolution rate and consequently improved bioavailability.